1. Field of the Invention
The invention relates to a lighting arrangement comprising a fluorescent lamp (or tube) and at least one light emitting diode (or LED), which is provided in particular for the interior lighting in a vehicle, in particular in a passenger aircraft.
2. Discussion of the Prior Art
Hitherto fluorescent lamps have predominantly been used for illuminating the interior of an aircraft. The user of fluorescent lamps is advantageous insofar as they make it possible to produce white light with a frequency spectrum which is pleasant for the human eye, with a particularly high light yield. The advantage of a high light yield is of great significance in particular in regard to the interior lighting of a vehicle, especially as here on the one hand the space available for lighting units is seriously restricted. The constricted space circumstances and the necessarily good insulation of the passenger cabin of a passenger aircraft on the other hand mean that the loss heat generated by the lighting arrangement is only comparatively poorly dissipated.
With the exclusive use of fluorescent lamps however it is on the other hand scarcely possible to alter the brightness of the interior lighting or to vary the colour spectrum thereof. That is found to be a disadvantage in many situations. In the design of a modern lighting arrangement, particularly in aircraft engineering, use is increasingly frequently made of the realisation that the mood and thus the wellbeing of the aircraft passengers, particularly in the case of long intercontinental flights, can be positively influenced by adapting the interior lighting to the daytime situation. Such lighting concepts are also summarised by using the term ‘mood lighting’. Thus for example interior lighting with a high proportion of blue has a calming effect and can thus promote relaxation of the passengers during a night flight. Equally a continuous and slow change in the lighting mood which for example simulates the change in light which takes place during a sunrise or sunset, can be desirable.
In order to permit a variation of that nature in the lighting effect, light emitting diodes are increasingly used for the purposes of interior lighting in an aircraft. A light emitting diode however in itself has the disadvantage, in relation to a fluorescent lamp, of a comparatively low level of brightness and a comparatively high level of lost power which is dissipated in the form of heat. The respective advantages of fluorescent lamps and light emitting diodes are synergistically utilised by the use of a hybrid lighting arrangement in which a white basic light component is produced by fluorescent lamps and the colour spectrum of which is modified by means of coloured light emitting diodes. Such a hybrid lighting arrangement however frequently takes up a comparatively large amount of space and therefore for precisely that reason can be only limitedly used in an aircraft.